Collagen drinks are, apparently, all the rage in Japan and yet another secret weapon for achieving the porcelain complexion of a geisha. There are several collagen drinks on the Japanese market, but Toki is the one that is getting attention in the US.
Toki's marketing department has quickly cottoned on to the fact that anti-aging cosmetics are often presented to a gullible public as the results of happy accidents (StriVectin, for example, was supposed to have started out as a stretch mark cream that was mistakenly applied to the face by testers who then witnessed the miraculous disappearance of their wrinkles). The origination myth that comes with Toki is that it was originally an oral supplement for sufferers of painful joints. Not only were their creaky knees oiled, but the collagen gave them glowing and youthful skin.
Collagen supplements are indeed prescribed to reduce the pain associated with rheumatoid arthritis. There are trials that back this up. However, the results are not earth shattering, but merely suggest that oral collagen may help a small minority. Now what about oral collagen and the skin? I found only one study, conducted in Japan, that says that taking collagen supplements had a visibly positive effect on the skin.
Given that Toki costs $150 for 60 day's worth, I think I need a bit more convincing. I'd also like to know from whence they get the collagen. Marine or bovine sources are typical in cosmetics. Why should we care? Well, too much estrogen can lead to cancer and some ingredients mimic human estrogen. The Sprecher Institute for Comparative Cancer Research at Cornell University lists the following cosmetic ingredients as possible sources of estrogen: parabens, placental extracts and benzophenones. Placental extracts can be a source of collagen, hence the potential concern.